The progress of g-C3N4 in photocatalytic H2 evolution: From fabrication to modification

Coordination Chemistry Reviews, Journal Year: 2023, Volume and Issue: 500, P. 215489 - 215489

Published: Nov. 2, 2023

Language: Английский

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Carbon nitride based materials: more than just a support for single-atom catalysis

Chemical Society Reviews, Journal Year: 2023, Volume and Issue: 52(15), P. 4878 - 4932

Published: Jan. 1, 2023

Recently, the missing link between homogeneous and heterogeneous catalysis has been found it was named single-atom (SAC). However, SAC field still faces important challenges, one of which is controlling bonding/coordination single atoms support in order to compensate for increase surface energy when particle size reduced due atomic dispersion. Excellent candidates meet this requirement are carbon nitride (CN)-based materials. Metal can be firmly trapped nitrogen-rich coordination sites CN materials, makes them a unique class hosts preparing catalysts (SACs). As most promising two-dimensional supports stabilize isolated metal atoms, materials have increasingly employed SACs. Herein, we will cover recent advances single-atoms supported by In review, characterization techniques challenges faced topic discussed, commonly synthetic methods delineated different Finally, catalytic performance SACs based on nitrides reviewed with special focus their photocatalytic applications. particular, prove as non-innocent support. The relationship two-way, where change electronic properties support, while features matrix tune activity reactions. highlight frontiers field, including analytical method development, truly controlled methods, allowing fine control loading multi-element synthesis, how understanding two-way exchange behind push next level.

Language: Английский

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Single-Atom Cu Channel and N-Vacancy Engineering Enables Efficient Charge Separation and Transfer between C₃N₄ Interlayers for Boosting Photocatalytic Hydrogen Production

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(9), P. 6280 - 6288

Published: April 21, 2023

Polymeric carbon nitride (C3N4) has attracted great attention in photocatalysis due to its low-cost, visible-light response, and environment-friendly merits. However, the catalytic efficiency of pristine bulk C3N4 is severely limited by poor photoinduced electron/hole pair separation interlayer charge transport. Herein, single-atom Cu bridged into sheet interlayers through thermal condensation self-assembly supramolecules precursors melamine–cyanuric acid monomers. Simultaneously, N vacancies are engineered only gradient temperature. The bridges serve as electron channels promote experimental results calculations demonstrate that break symmetry C3N4, allowing more electrons pass delocalized π-conjugated network sites, which facilitates transfer between layers, resulting effective pairs, optimal distribution, lower hydrogen evolution barrier. As a result, photocatalyst at stationary point with 1 wt % Pt cocatalyst presents high photocatalytic production rate (11.23 mmol g–1 h–1), reaching apparent quantum yield 31.60% 420 nm. It noted still exhibits 605.15 μmol h–1 absence cocatalyst.

Language: Английский

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Co-catalytic metal–support interactions in single-atom electrocatalysts

Nature Reviews Materials, Journal Year: 2024, Volume and Issue: 9(3), P. 173 - 189

Published: Jan. 10, 2024

Language: Английский

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Unveiling the Bifunctional Photo/Electrocatalytic Activity of In Situ Grown CdSe QDs on g-C₃N₄ Nanosheet Z-Scheme Heterostructures for Efficient Hydrogen Generation

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(2), P. 691 - 702

Published: Jan. 2, 2024

The successive ionic layer adsorption and reaction (SILAR) method was used to deposit several CdSe quantum dots (QDs) on the surface of g-C3N4 nanosheets. In comparison single moiety g-C3N4, as-prepared heterostructures displayed an improved bifunctional photo- electrocatalytic activity for oxygen (OER) hydrogen evolution reactions (HER). Significantly, 30 SILAR cycles optimized QDs/g-C3N4 heterostructure exhibited high performances stabilities OER HER in alkaline conditions. catalyst also efficient photocatalytic toward H2 produced 4306 μmol gas with 23.8% apparent yield presence triethanolamine as a sacrificial agent. Photoluminescence spectroscopy, electron paramagnetic resonance, impedance spectroscopy suggest that synergy between nanosheets QDs leads higher catalytic activities, indicated by low overpotentials 147 218 mV obtain 10 mA cm–2 current density reactions, respectively. Furthermore, situ Fourier transform infrared liquid chromatography–mass high-performance chromatography were conducted determine photochemical intermediate products confirm successful oxidation TEOA capturing holes. outcome is accordance fact photogenerated electrons are transferred from conduction band (CB) valence (VB) Z-scheme manner.

Language: Английский

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Single Atom Catalysts for Selective Methane Oxidation to Oxygenates

ACS Nano, Journal Year: 2022, Volume and Issue: 16(6), P. 8557 - 8618

Published: May 31, 2022

Direct conversion of methane (CH4) to C1–2 liquid oxygenates is a captivating approach lock carbons in transportable value-added chemicals, while reducing global warming. Existing approaches utilizing the transformation CH4 fuel via tandemized steam reforming and Fischer–Tropsch synthesis are energy capital intensive. Chemocatalytic partial oxidation remains challenging due negligible electron affinity, poor C–H bond polarizability, high activation barrier. Transition-metal stoichiometric catalysts harsh oxidants reaction conditions perform poorly with randomized product distribution. Paradoxically, which active enough break also promote overoxidation, resulting CO2 generation reduced carbon balance. Developing can bonds selectively make useful chemicals at mild vital commercialization. Single atom (SACs) specifically coordinated metal centers on support have displayed intrigued reactivity selectivity for oxidation. SACs significantly reduce induced electrostatic polarization facilitate accelerated rate low temperature. The distinct metal–support interaction stabilize intermediate prevent overoxidation products. present review accounts recent progress field selective oxygenates. chemical nature catalytic sites, effects interaction, stabilization species minimize thoroughly discussed forward-looking perspective improve performance.

Language: Английский

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Selective Photocatalytic Reduction of CO₂ to CO Mediated by Silver Single Atoms Anchored on Tubular Carbon Nitride

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(26)

Published: April 28, 2023

Artificial photosynthesis is a promising strategy for converting carbon dioxide (CO2 ) and water (H2 O) into fuels value-added chemical products. However, photocatalysts usually suffered from low activity product selectivity due to the sluggish dynamic transfer of photoexcited charge carriers. Herein, we describe anchoring Ag single atoms on hollow porous polygonal C3 N4 nanotubes (PCN) form photocatalyst Ag1 @PCN with Ag-N3 coordination CO2 photoreduction using H2 O as reductant. The as-synthesized exhibits high CO production rate 0.32 μmol h-1 (mass catalyst: 2 mg), (>94 %), an excellent stability in long term. Experiments density functional theory (DFT) reveal that strong metal-support interactions (Ag-N3 favor *CO2 adsorption, *COOH generation desorption, accelerate carriers between atoms, thereby accounting enhanced selectivity. This work provides deep insight important role enhancing photoactivity photoreduction.

Language: Английский

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Directional Charge Transfer Channels in a Monolithically Integrated Electrode for Photoassisted Overall Water Splitting

ACS Nano, Journal Year: 2023, Volume and Issue: 17(4), P. 3465 - 3482

Published: Feb. 10, 2023

Photoelectrocatalytic performance of a system is fundamentally determined by the full absorption sunlight and high utilization photoexcited carriers, but efficiency latter largely limited inefficient charge transfer from absorber to reactive sites. Here, we propose construct directional channels in monolithically integrated electrode, taking carbon dots/carbon nitride (CCN) nanotubes FeOOH/FeCo layered double hydroxide (FFC) nanosheets as representative, boost photoassisted overall water splitting performance. Detailed experimental investigations DFT calculations demonstrate that interfacial C-O-Fe bonds between CCN FFC act channels, facilitating migration photogenerated carriers surfaces. Moreover, situ oxidized Fe/Co species holes trigger lattice oxygen activation, realizing construction Fe-Co dual-site catalytic center efficiently lowering barrier energy for oxidation. As result, CCN@FFC electrode shows multiple functionalities photoelectrocatalysis: only low overpotential 68 mV, 182 1.435 V required deliver 10 mA cm-2 current densities HER, OER, splitting, respectively. This modulation strategy may facilitate design highly active cost-effective multifunctional catalysts conversion storage.

Language: Английский

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Bio‐Inspired Supramolecular Self‐Assembled Carbon Nitride Nanostructures for Photocatalytic Water Splitting

Advanced Materials, Journal Year: 2023, Volume and Issue: 36(2)

Published: Sept. 12, 2023

Abstract Fast production of hydrogen and oxygen in large amounts at an economic rate is the need hour to cater needs most awaited energy, a futuristic renewable energy solution. Production through simple water splitting via visible light photocatalytic approach using sunlight considered as one promising sustainable approaches for generating clean fuels. For this purpose, variety catalytic techniques novel catalysts have been investigated. Among these catalysts, carbon nitride presently deemed best candidates photocatalysis due its unique molecular structure adequate visible‐range bandgap. Its bandgap can be further engineered by structural morphological manipulation or doping/hybridization. numerous synthetic nitrides, supramolecular self‐assembly recently developed elegant bottom‐up strategies it bio‐inspired provides facile eco‐friendly route synthesize high surface area with superior features other semiconducting properties. The current review article broadly covers synthesis nanostructures their water‐splitting applications comprehensive outlook on future directions.

Language: Английский

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Unraveling the Synergy Mechanism between Photocatalysis and Peroxymonosulfate Activation on a Co/Fe Bimetal-Doped Carbon Nitride

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(13), P. 8973 - 8986

Published: June 22, 2023

Fenton-like catalysis based on peroxymonosulfate (PMS) activation has shown great potential in the treatment of organic wastewater. Heterogeneous catalysts containing transition metal active sites are highly efficient for PMS activation. However, reduction oxidized was usually not prompt due to sluggish reaction kinetics, which caused insufficient redox cycle and further hampered efficiency. Recent studies have that synergy effect between photocatalysis may address above obstacle boost overall a deeper understanding this is still missing, making it difficult be rationally controlled; thus, poor frequently reported. Herein, Co/Fe bimetal-doped graphitic carbon nitride (g-C3N4) designed representatively through systematical characterization theoretical calculation, revealed profoundly determined by competitive role hole system adsorbed metastable PMS* catalyst surface, furthermore, can manipulated; when doping ratio 2.5:2.5, as-prepared g-C3N4 with moderate valence band position endow an optimized photo-Fenton-like synergistic highest catalytic degradation performance. This work sheds light rational design catalysts.

Language: Английский

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